Integration of high-risk human papillomavirus: a key event in cervical carcinogenesis?

Identification of eight candidate target genes of the recurrent 3p12-p14 loss in cervical cancer by integrative genomic profiling

The pathogenetic role, including its target genes, of the recurrent 3p12-p14 loss in cervical cancer has remained unclear. To determine the onset of the event during carcinogenesis, we used microarray techniques and found that the loss was the most frequent 3p event, occurring in 61% of 92 invasive carcinomas, in only 2% of 43 high-grade intraepithelial lesions (CIN2/3), and in 33% of 6 CIN3 lesions adjacent to invasive carcinomas, suggesting a role in acquisition of invasiveness or early during the invasive phase. We performed an integrative DNA copy number and expression analysis of 77 invasive carcinomas, where all genes within the recurrent region were included. We selected eight genes, THOC7, PSMD6, SLC25A26, TMF1, RYBP, SHQ1, EBLN2, and GBE1, which were highly down-regulated in cases with loss, as confirmed at the protein level for RYBP and TMF1 by immunohistochemistry. The eight genes were subjected to network analysis based on the expression profiles, revealing interaction partners of proteins encoded by the genes that were coordinately regulated in tumours with loss. Several partners were shared among the eight genes, indicating crosstalk in their signalling. Gene ontology analysis showed enrichment of biological processes such as apoptosis, proliferation, and stress response in the network and suggested a relationship between down-regulation of the eight genes and activation of tumourigenic pathways. Survival analysis showed prognostic impact of the eight-gene signature that was confirmed in a validation cohort of 74 patients and was independent of clinical parameters. These results support the role of the eight candidate genes as targets of the 3p12-p14 loss in cervical cancer and suggest that the strong selection advantage of the loss during carcinogenesis might be caused by a synergetic effect of several tumourigenic processes controlled by these targets.

Prediction of outcome in patients with low-grade squamous intraepithelial lesions by fluorescence in situ hybridization analysis of human papillomavirus, TERC, and MYC

BACKGROUND

Cytology is an excellent method with which to diagnose preinvasive lesions of the uterine cervix, but it suffers from limited specificity for clinically significant lesions. Supplementary methods might predict the natural course of the detected lesions. The objective of the current study was to test whether a multicolor fluorescence in situ hybridization (FISH) assay might help to stratify abnormal results of Papanicolaou tests.

METHODS

A total of 219 liquid-based cytology specimens of low-grade squamous intraepithelial lesions (LSIL), 49 atypical squamous cells of undetermined significance (ASCUS) specimens, 52 high-grade squamous intraepithelial lesion (HSIL) specimens, and 50 normal samples were assessed by FISH with probes for the human papillomavirus (HPV), MYC, and telomerase RNA component (TERC). Subtyping of HPV by polymerase chain reaction (PCR) was performed in a subset of cases (n=206).

RESULTS

There was a significant correlation found between HPV detection by FISH and PCR (P<.0001). In patients with LSILs, the presence of HPV detected by FISH was significantly associated with disease progression (P<.0001). An increased MYC and/or TERC gene copy number (>2 signals in>10% of cells) prevailed in 43% of ASCUS specimens and was more frequent in HSIL (85%) than in LSIL (33%) (HSIL vs LSIL: P<.0001). Increased TERC gene copy number was significantly correlated with progression of LSIL (P<.01; odds ratio, 7.44; area under the receiver operating characteristic curve, 0.73; positive predictive value, 0.30; negative predictive value, 0.94) CONCLUSIONS: The detection of HPV by FISH analysis is feasible in liquid-based cytology and is significantly correlated with HPV analysis by PCR. The analysis of TERC gene copy number may be useful for risk stratification in patients with LSIL.

Human papillomavirus early proteins and apoptosis

INTRODUCTION

The human papillomavirus (HPV) associated apoptosis can be primarily attributed to some early proteins, such as E2, E5, E6, E7, and so on. Though these proteins have a low molecular size, they are capable to interact with a series of host cellular regulation proteins to induce or inhibit apoptosis. The oncoproteins E6 can inhibit the apoptosis mainly through p53 pathway. The E5 protein can protect cells from tumor necrosis factor-related apoptosis. The protein E2 protein have regulatory functions in viral transcription and induction of apoptosis. The oncoprotein E7 plays the role in both apoptosis activation and inhibition. In addition, the HPV full-length E2 proteins involve in activating or repressing the transcription of E6/E7, so as to regulating the apoptosis caused by E6 and E7.

MATERIALS AND METHODS

We search major databases (such as Elsevier) with the following selection criteria: HPV, early protein, apoptosis.

CONCLUSIONS

In this review, we summary the literature related with E2, E5, E6, and E7 proteins, and describe the regulatory principles and specific mechanism by which HPV early proteins can interfere with apoptosis and trigger gynaecopathias for women.

Differential methylation of E2 binding sites in episomal and integrated HPV 16 genomes in preinvasive and invasive cervical lesions

Enhanced expression of the HPV 16 E6-E7 oncogenes may trigger neoplastic transformation of the squamous epithelial cells at the uterine cervix. The HPV E2 protein is a key transcriptional regulator of the E6-E7 genes. It binds to four E2 binding sites (E2BSs 1-4) in the viral upstream regulatory region (URR). Modification of E2 functions, for example, by methylation of E2BSs is hypothesized to trigger enhanced expression of the viral E6-E7 oncogenes. In the majority of HPV-transformed premalignant lesions and about half of cervical carcinomas HPV genomes persist in an extra-chromosomal, episomal state, whereas they are integrated into host cells chromosomes in the remaining lesions. Here we compared the methylation profile of E2BSs 1-4 of the HPV 16 URR in a series of 18 HPV16-positive premalignant lesions and 33 invasive cervical cancers. CpGs within the E2BSs 1, 3, and 4 were higher methylated in all lesions with only episomal HPV16 genomes compared with lesions displaying single integrated copies. Samples with multiple HPV16 integrated copies displayed high methylation levels for all CpGs suggesting that the majority of multiple copies were silenced by extensive methylation. These data support the hypothesis that differential methylation of the E2BSs 1, 3 and 4 is related to the activation of viral oncogene expression in cervical lesions as long as the viral genome remains in the episomal state. Once the virus becomes integrated into host cell chromosomes these methylation patterns may be substantially altered due to complex epigenetic changes of integrated HPV genomes.

The biology and life-cycle of human papillomaviruses

Human papillomaviruses (HPVs) comprise a diverse group, and have different epithelial tropisms and life-cycle strategies. Many HPVs are classified as low-risk, as they are only very rarely associated with neoplasia or cancer in the general population. These HPVs typically cause inapparent/inconspicuous infections, or benign papillomas, which can persist for months or years, but which are eventually resolved by the host's immune system. Low-risk HPVs are difficult to manage in immunosuppressed people and in individuals with genetic predispositions, and can give rise to papillomatosis, and in rare instances, to cancer. The high-risk HPV types are, by contrast, a cause of several important human cancers, including almost all cases of cervical cancer, a large proportion of other anogenital cancers and a growing number of head and neck tumours. The high-risk HPV types constitute a subset of the genus Alphapapillomavirus that are prevalent in the general population, and in most individuals cause only inconspicuous oral and genital lesions. Cancer progression is associated with persistent high-risk HPV infection and with deregulated viral gene expression, which leads to excessive cell proliferation, deficient DNA repair, and the accumulation of genetic damage in the infected cell. Although their life-cycle organisation is broadly similar to that of the low-risk HPV types, the two groups differ significantly in their capacity to drive cell cycle entry and cell proliferation in the basal/parabasal cell layers. This is thought to be linked, at least in part, to different abilities of the high- and low-risk E6 proteins to modulate the activity of p53 and PDZ-domain proteins, and the differential ability of the E7 proteins to target the several different members of the retinoblastoma protein family. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

Host-cell factors involved in papillomavirus entry

Papillomaviruses infect skin and mucosa where they induce warts and cancers. For entry to occur, they sequentially engage numerous host proteins, allowing them to deliver their genetic information into target cells. This multistep process starts with initial binding via its L1 major capsid protein, followed by structural changes of the capsid on the cell surface, engagement of different receptors, and endocytosis. The post-entry phase includes capsid disassembly, endosomal escape of a complex of the minor capsid protein L2 and the viral genome, its transport into the nucleus, and accumulation at nuclear substructures. This review summarizes the current knowledge of the papillomavirus entry pathway and the role of cellular proteins involved in this course of events.

Future directions and treatment strategies for head and neck squamous cell carcinomas

Head and neck cancer is a devastating disease that afflicts many individuals worldwide. Conventional therapies are successful in only a limited subgroup and often leave the patient with disfigurement and long lasting adverse effects on normal physiologic functions. The field is in dire need of new therapies. Oncolytic viral as well as targeted therapies have shown some success in other malignancies and are attractive for the treatment of head and neck cancer. Recently, it has been shown that a subset of head and neck cancers is human papillomavirus (HPV) positive and that this subset of cancers is biologically distinct and more sensitive to chemoradiation therapies although the underlying mechanism is unclear. However, chemoresistance remains a general problem. One candidate mediator of therapeutic response, which is of interest for the targeting of both HPV-positive and -negative tumors is the human DEK proto-oncogene. DEK is upregulated in numerous tumors including head and neck cancers regardless of their HPV status. Depletion of DEK in tumor cells in culture results in sensitivity to genotoxic agents, particularly in rapidly proliferating cells. This suggests that tumors with high DEK protein expression may be correlated with poor clinical response to clastogenic therapies. Targeting molecules such as DEK in combination with new and/or conventional therapies, holds promise for novel future therapeutics for head and neck cancer.

The distribution of human papillomavirus in tissues from patients with head and neck squamous cell carcinoma

Several types of HPVs have been shown to be associated with the development of malignant cancers in various head and neck tumors. More information on the HPV prevalence in patients with head and neck squamous cell carcinomas (SCCs) need to be obtained. In this study, formalin-fixed and paraffin-embedded tissues of 93 pathologically diagnosed head and neck SCC patients were collected from Peking University Cancer Hospital. HPV DNA sequences in tumor tissues were screened by a commercial Luminex technique for HPVs and HPV-specific PCR assays. Presence of HPV16/18 oncoprotein in tumor tissues was assessed by immunohistochemistry (IHC) with HPV16/18 E6-specific antibodies. Of the 93 patients, 16 (17.2%) cases were found to be HPV DNA-positive, including 7 HPV18-positive, 8 HPV16-positive and 1 HPV52-positive. IHC assays demonstrated that 31.2% (29/93) tested sections showed positive signals in the tumor cells. The total positive rate of HPV genome and its encoding products in the tested samples was 44.1% (41/93). Further analyses revealed that HPV infections in head and neck SCCs were significantly related with the tumor anatomic sites, showing decreasing tendency from outside (lip cancer) to inside (laryngeal cancer), but had no correlation with pathological, clinical grades and age of the patients. In all, HPV infections are commonly identified in the tumor tissues of patients with head and neck SCCs, in which HPV16 and 18 are the most prevalent HPV genotypes. Direct detection of high-risk HPV oncoprotein by IHC may be a good tool for classifying a tumor as truly HPV-associated.

Biology of human papillomavirus infection and immune therapy for HPV-related head and neck cancers

This article outlines the biology of human papillomavirus (HPV) infection of human mucosa and the cellular pathways that are altered through viral infection. The article provides a conceptual framework with which to understand the 2 major immunologic strategies to address HPV-related diseases: (1) prevention of primary HPV infection through the use of prophylactic vaccines and (2) treatment of established infection and diseases through therapeutic vaccines. Nonimmunologic therapy that targets cellular dysregulation induced by HPV infection is also discussed. The challenges in actualizing these conceptually attractive therapies on both a societal and biological level are examined.

Epithelial cell responses to infection with human papillomavirus

Human papillomavirus (HPV) infection of the genital tract is common in young sexually active individuals, the majority of whom clear the infection without overt clinical disease. Most of those who do develop benign lesions eventually mount an effective cell-mediated immune (CMI) response, and the lesions regress. Regression of anogenital warts is accompanied histologically by a CD4(+) T cell-dominated Th1 response; animal models support this and provide evidence that the response is modulated by antigen-specific CD4(+) T cell-dependent mechanisms. Failure to develop an effective CMI response to clear or control infection results in persistent infection and, in the case of the oncogenic HPVs, an increased probability of progression to high-grade intraepithelial neoplasia and invasive carcinoma. Effective evasion of innate immune recognition seems to be the hallmark of HPV infections. The viral infectious cycle is exclusively intraepithelial: there is no viremia and no virus-induced cytolysis or cell death, and viral replication and release are not associated with inflammation. HPV globally downregulates the innate immune signaling pathways in the infected keratinocyte. Proinflammatory cytokines, particularly the type I interferons, are not released, and the signals for Langerhans cell (LC) activation and migration, together with recruitment of stromal dendritic cells and macrophages, are either not present or inadequate. This immune ignorance results in chronic infections that persist over weeks and months. Progression to high-grade intraepithelial neoplasia with concomitant upregulation of the E6 and E7 oncoproteins is associated with further deregulation of immunologically relevant molecules, particularly chemotactic chemokines and their receptors, on keratinocytes and endothelial cells of the underlying microvasculature, limiting or preventing the ingress of cytotoxic effectors into the lesions. Recent evidence suggests that HPV infection of basal keratinocytes requires epithelial wounding followed by the reepithelization of wound healing. The wound exudate that results provides a mechanistic explanation for the protection offered by serum neutralizing antibody generated by HPV L1 virus-like particle (VLP) vaccines.

Lipoprotein lipase is frequently overexpressed or translocated in cervical squamous cell carcinoma and promotes invasiveness through the non-catalytic C terminus

Background:

We studied the biological significance of genes involved in a novel t(8;12)(p21.3;p13.31) reciprocal translocation identified in cervical squamous cell carcinoma (SCC) cells.

Methods:

The rearranged genes were identified by breakpoint mapping, long-range PCR and sequencing. We investigated gene expression in vivo using reverse-transcription PCR and tissue microarrays, and studied the phenotypic consequences of forced gene overexpression.

Results:

The rearrangement involved lipoprotein lipase (LPL) and peroxisome biogenesis factor-5 (PEX5). Whereas LPL–PEX5 was expressed at low levels and contained a premature stop codon, PEX5–LPL was highly expressed and encoded a full-length chimeric protein (including the majority of the LPL coding region). Consistent with these findings, PEX5 was constitutively expressed in normal cervical squamous cells, whereas LPL expression was negligible. The LPL gene was rearranged in 1 out of 151 cervical SCCs, whereas wild-type LPL overexpression was common, being detected in 10 out of 28 tissue samples and 4 out of 10 cell lines. Forced overexpression of wild-type LPL and PEX5–LPL fusion transcripts resulted in increased invasiveness in cervical SCC cells, attributable to the C-terminal non-catalytic domain of LPL, which was retained in the fusion transcripts.

Conclusion:

This is the first demonstration of an expressed fusion gene in cervical SCC. Overexpressed wild-type or translocated LPL is a candidate for targeted therapy.

Non-random integration of the HPV genome in cervical cancer

HPV DNA integration into the host genome is a characteristic but not an exclusive step during cervical carcinogenesis. It is still a matter of debate whether viral integration contributes to the transformation process beyond ensuring the constitutive expression of the viral oncogenes. There is mounting evidence for a non-random distribution of integration loci and the direct involvement of cellular cancer-related genes. In this study we addressed this topic by extending the existing data set by an additional 47 HPV16 and HPV18 positive cervical carcinoma. We provide supportive evidence for previously defined integration hotspots and have revealed another cluster of integration sites within the cytogenetic band 3q28. Moreover, in the vicinity of these hotspots numerous microRNAs (miRNAs) are located and may be influenced by the integrated HPV DNA. By compiling our data and published reports 9 genes could be identified which were affected by HPV integration at least twice in independent tumors. In some tumors the viral-cellular fusion transcripts were even identical with respect to the viral donor and cellular acceptor sites used. However, the exact integration sites are likely to differ since none of the integration sites analysed thus far have shown more than a few nucleotides of homology between viral and host sequences. Therefore, DNA recombination involving large stretches of homology at the integration site can be ruled out. It is however intriguing that by sequence alignment several regions of the HPV16 genome were found to have highly homologous stretches of up to 50 nucleotides to the aforementioned genes and the integration hotspots. One common region of homologies with cellular sequences is between the viral gene E5 and L2 (nucleotides positions 4100 to 4240). We speculate that this and other regions of homology are involved in the integration process. Our observations suggest that targeted disruption, possibly also of critical cellular genes, by HPV integration remains an issue to be fully resolved.

Impact of foreign DNA integration on tumor biology and on evolution via epigenetic alterations

The insertion of foreign DNA into mammalian genomes can alter their methylation and transcription patterns at remote sites from the locus of foreign DNA integration. The mechanisms leading to these fundamental changes and their frequencies are unknown. Sites and extent of changes in the recipient cells might depend on the location of foreign DNA integration. In the second part of this review, it will be hypothesized that the insertion event itself, for example, of tumor viral DNA via its epigenetic genome-wide consequences, plays an important role in oncogenesis. During evolution, the impact of ancient retrotransposon or retroviral genomes and the ensuing epigenetic alterations in the recipient genomes might have generated cells with completely different transcriptional profiles. Due to the continued presence of the transgenomes these alterations were genetically stable and were selected for or against by the environmental conditions prevalent at the time. These evolutionary effects are very different from those postulated for insertional mutagenesis, added genetic information or regulatory elements placed into the vicinity of cellular functions.

Correlation between ebv co-infection and HPV16 genome integrity in Tunisian cervical cancer patients

Infection with high risk Human papillomavirus (HR-HPV) is necessary but not sufficient to cause cervical carcinoma. This study explored whether multiple HR-HPV or coinfection with Epstein-Barr virus (EBV) influence the integration status of HPV16 genome. The presence and typing of HPV in a series of 125 cervical specimens were assessed by polymerase chain reaction (PCR) using the specific primers for the HPV L1 region. As for EBV infection, the viral EBNA1 gene was used for its detection through PCR amplification. Disruption of the HPV E2 gene was assessed by amplification of the entire E2 gene with single set of primers, while E2 transcripts were evaluated by a reverse transcription PCR method (RT-PCR). The overall prevalence of HPVDNA was of 81.8% in cervical cancers versus 26.9% in benign lesions. In HPV positive cases, HPV16 and HPV18 were the most prevalent types, followed by HPV types 33, 31. EBV EBNA1 prevalence was statistically more frequent in cervical carcinomas than in benign lesions (29.5%, vs 9.6%; P=0.01). No viral infection was detected in healthy control women. The uninterrupted E2 gene was correlated with the presence of E2 transcripts originating from the HPV episomal forms. It was observed that integration was more common in HPV18 and EBV coinfection. The presence of EBV caused a five-fold [OR= 5; CI= 1.15-21.8; P = 0.04] increase in the risk of HPV16 genome integration in the host genome. This study indicates that EBV infection is acting as a cofactor for induction of cervical cancer by favoring HPVDNA integration.

[HPV-associated carcinomas of the female genital tract. Molecular mechanisms of development]

Infections with human papillomaviruses (HPV) are a common occurrence in both men and women. In contrast HPV-associated neoplasias are relatively rare and occur only in certain areas of the body. The virus has obviously developed efficient mechanisms for its persistence without inducing too much damage to the host. The formation of neoplasia seems to be more an exception. Epigenetic mechanisms play an important role in the regulation of viral gene expression. Investigations have indicated that exactly the transition from the permissive infection stage to a transformation stage, where neoplastic alterations can occur due to expression of the viral oncogenes, is associated with certain methylation patterns of the viral genome which promote the expression of the oncogenes E6 and E7. The transforming stage is seen as the actual carcinogenic event and can be immunohistochemically detected by the biomarker p16(INK4a).

Characterization of the human papillomavirus (HPV) integration sites into genital cancers

Oncogenic HPVs have been found frequently integrated into human genome of invasive cancers and chromosomal localization has been extensively investigated in cervical carcinoma. Few studies have analyzed the HPV integration loci in other genital cancers. We have characterized the integration sites of HPV16 in invasive penile carcinoma by means of Alu-HPV-based PCR. Nucleotide sequence analysis of viral-human DNA junctions showed that HPV integration occurred in one case within the chromosome 8q21.3 region, in which the FAM92A1 gene is mapped, and in the second case inside the chromosome 16p13.3, within the intronic region of TRAP1 gene. These results confirm previous observations, summarized in a systematic review of the literature, on the HPV integration events in gene loci relevant to cancer pathogenesis.

HPV-related (pre)malignancies of the female anogenital tract in renal transplant recipients

Renal transplantations (RTs) are performed routinely in many countries. After RT, the administration of lifelong immunosuppressive therapy is required. As a consequence, renal transplant recipients (RTRs) have a high risk to develop virus-associated (pre)malignancies, such as Human papillomavirus (HPV) related anogenital (pre)malignancies. It is known that the majority of the RTRs are infected with HPV and that these women have a 14-fold increased risk of cervical cancer, up to 50-fold of vulvar cancer and up to 100-fold of anal cancer. Often, treatment of these lesions requires concessions and may be suboptimal as radiation therapy and extensive surgery may damage the renal transplant. Therefore, prognosis may be compromised due to inadequately treated malignancies. Especially for these immunocompromised patients prevention is of utmost importance. Yearly cervical cancer screening for RTRs is advised, but appears to be executed poorly. For the future, optimizing screening and prevention of anogenital (pre)malignancies is an important issue for women after RT. This review gives a broad overview of all aspects regarding HPV-related (pre)malignancies of the female anogenital tract in RTRs.

Type-dependent E6/E7 mRNA expression of single and multiple high-risk human papillomavirus infections in cervical neoplasia

BACKGROUND

Coinfection with multiple HPV types is common in cervical lesions, but the biological significance of the individual infections is difficult to establish. Expression of oncogenic E6/E7 HPV mRNA is correlated to risk of malignant progression, commercial assays for genotyping E6/E7 mRNA of all HR-HPV are lacking.

OBJECTIVES

To characterize the tendency of 12 HR-HPV to express mRNA, correlated to the severity of the cervical lesion. Furthermore, we wanted to analyse mRNA expression in multiple infections, in order to establish which genotype may be responsible for cellular transformation.

STUDY DESIGN

245 samples from women with normal histology, various grades of dysplasia (cervical intraepithelial neoplasia grade 1-3), and cancer, were analysed for presence and genotyping of HPV DNA and mRNA using an in house real-time PCR test.

RESULTS

Presence of mRNA was detected for 64% of the in total 422 HPV infections present in the samples, and more commonly in high-grade lesions. In 88% of DNA-positive samples from CIN2+ lesions, mRNA could be detected, compared to 33% of DNA-positive samples from women in screening with normal cytology. The genotype most prone to express mRNA in high-grade lesions was HPV45, followed by HPV16 and HPV31, less prone was HPV59. Expression of mRNA was significantly enhanced in CIN2+ lesions, an association also found for HPV16. In 52% of multiple infections (in which mRNA expression was generally more common), more than one genotype expressed mRNA, a phenomenon increasing with severity of lesion. Presence of mRNA could more often be detected in samples with multiple infections than in samples with single infections.

CONCLUSIONS

The frequent expression of E6/E7 by HPV45 may promote oncogenicity and could be of clinical importance. Since presence of E6/E7 mRNA was common in multiple infections regardless of histology, multiple infection could be a clinically important finding. In multiple HPV infections, mRNA testing may identify the genotype that causes transformation. However, since mRNA expression of several genotypes in one sample is common, further and larger studies using complementary techniques are required.

[High-risk human papilloma virus associated oropharynx squamous cell carcinomas: clinical, biological implications and therapeutical perspectives]

The infection of the head and neck epithelium by high-risk human papillomaviruses (HPV) is a risk factor for cancer onset and development. The incidence of HPV-related head and neck squamous cell carcinoma is currently increasing. These lesions display distinct clinical features. HPV positive patients are often younger and have a smaller history of tobacco smoking and alcohol drinking, but have a history of virus-transmitting sex practices. HPV-related tumours are mainly found in the oropharynx, are more associated to a local lymph node invasion and display a poorly differentiated morphology. Despite these more aggressive features, HPV-positive head and neck squamous cell carcinomas correlate with an improved local control, disease-free and global survival. It is thought that HPV-driven specific biologic abnormalities underlie higher tumour sensitivity to chemotherapeutic drugs and ionizing radiations. The expression of the HPV E6 and E7 oncoproteins induce cell transformation by interfering with cell signalling pathways involved in apoptosis, cell cycle, angiogenesis and induce the overexpression of the CDKN2A gene. Therefore, alternative treatments based on therapies targeting these pathways in combination with radiation dose de-escalation could be proposed to HPV-positive patients, if they are properly and reliably identified.

Correlation between physical status of human papilloma virus and cervical carcinogenesis

The prevalence of human papilloma virus (HPV)-16 in patients with cervical cancer, the physical status of HPV-16 in patients with cervical lesions, and the role of HPV-16 integration in cervical carcinogenesis were investigated. HPV genotyping was performed by using PCR approach with the primer GP5+/GP6+ and type-specific primer on biopsy specimens taken operatively from 198 women. Multiple PCR was done to detect physical status of HPV-16 in a series of cervical liquid-based cytology samples and biopsy specimens obtained from different cervical lesions with HPV-16 infection, including 112 specimens with cervical cancer, 151 specimens with CIN I, 246 specimens with CIN and 120 specimens with CINIII. The results showed that there were 112 cervical cancer samples (56.57% of total cervical cancer patients) with HPV-16 infection. The frequency of HPV-16 pure integration was 65.18% (73/112), 56.57% (47/120), 23.58% (58/246) and 7.95% (12/151) in cervical cancer, CINIII, CINII and CINI patients respectively. In situ hybridization was performed on some paraffin-embedded sections of CINII, CINIII and cervical cancer to verify the physical status of HPV-16 infection. Significant difference was observed between cervical cancer and CIN I, CINII, CINIII in the frequency of HPV-16 integration (P<0.01). It is suggested that HPV-16 is the most prevalent type and is associated with cervical cancer. In the case of HPV-16 infection there are close associations between the severity of cervical lesions and the frequency of HPV-16 integration. The application of testing HPV genotyping and physical status based on detection of HC-II HPV DNA would be in favor of predicting the prognosis of cervical precancerosis and enhancing the screening accuracy of cervical cancer.

Silencing of multi-copy HPV16 by viral self-methylation and chromatin occlusion: a model for epigenetic virus-host interaction

In the present study, we used the human papillomavirus type 16 (HPV16)-positive cervical carcinoma cell line CaSki as a paradigmatic model to understand epigenetic silencing of viral multi-copy genomes. We show that most of the hypermethylated HPV16 copies are kept as 'occluded' chromatin that defines a condition where genes were refractory in their response to trans-acting transcription factors and to external reactivation efforts. This provides the first example that viral genomes are silenced by such a host cell mechanism, hitherto only known for endogenous genes to preserve a stable and robust phenotype. Moreover, considering an adaptive cross-talk between viral proteins and the epigenetic modification machinery, we demonstrate that particularly E2-but also ectopically delivered E6/E7-can induce significant de novo methylation within the enhancer and, to a less extent, within the promoter region. These data suggest that under certain physiological conditions, HPV can down-regulate its own gene expression, regardless of the presence of transcriptional activators. We propose that self-methylation of multi-copy HPV could be the first event prior to heterochromatin formation. These processes favour an 'occluded' chromatin conformation, finally being unresponsive to transcriptional activation. The shift from potentially competent heterochromatin towards an occluded state is basically irreversible, possibly using the same mechanism described for lineage differentiation. Along this line, it is tempting to speculate that virus-cell interaction is able to 'sense' viral copy number and down-regulates excess of gene activity in order to guarantee cell viability.

Genetic polymorphisms and cervical cancer development: ATM G5557A and p53bp1 C1236G

Persistent infections by high-risk types of human papillomavirus (HPV) have been established as the etiological agent of cervical cancer. The integration of the HPV genome into the host genome is a crucial step in cervical carcinogenesis, although, correct activation of DNA damage repair pathways will avoid the development of cancer. Recent data indicate that several polymorphisms of key regulators from the DNA damage repair pathway (i.e. 53BP1 and ATM) are associated with cancer development susceptibility. We have developed a hospital-based retrospective study considering 429 cervical specimens from women with different cervical lesions including invasive carcinoma. This study aimed to evaluate the role of the ATM D1853N (5557G>A) and 53bp1 D353E (1236C>G) polymorphisms in the development of cervical cancer, using TaqMan SNP Genotyping Assays. Statistical analysis revealed that ATM 5557GG homozygous individuals (OR=1.94; p=0.044) are at increased risk of developing LSIL, while for the 53BP1 1236C>G polymorphism no association was found. Nevertheless, we observed a tendency for an increased risk of LSIL in 53BP1 1236C allele carriers (OR=1.63; p=0.069). Logistic regression adjusted for age revealed no significant differences from the non-adjusted analysis. This is the first study to evaluate the role of ATM G5557A and P53BP1 C1236G polymorphisms in cervical cancer susceptibility. This study reveals a possible trend of both polymorphisms for a genetic susceptibility pattern of cervical cancer development. Hence, our results may be of interest for future understanding of the progression of cervical cancer.

New technologies for cervical cancer screening

New technologies for cervical cancer screening seek to provide an accurate, efficient and cost-effective way of identifying women at risk for cervical cancer. Current screening uses human papilloma virus DNA testing combined with cytology, and requires multiple visits at a great cost to the patient and society. New methods for screening include HPV diagnostics (detection of either the presence of human papilloma virus or integration of the virus into the host cell), proliferation, and detection of epigenetic changes, either in the host or virus. These methods show promise in changing the way that current cervical cancer screening is undertaken in low-and high-resource settings.

Type-specific human papillomavirus E6/E7 mRNA detection by real-time PCR improves identification of cervical neoplasia

DNA-based human papillomavirus (HPV) assays show high sensitivity but poor specificity in detecting high-grade cervical lesions. Assays detecting mRNA of the oncoproteins E6 and E7 show higher specificity but lack either detection of all high-risk HPV genotypes or the capacity to specify the detected genotypes. Therefore, a real-time PCR assay detecting type-specific E6/E7 mRNA was developed and the clinical performance evaluated. A total of 210 cervical LBC (liquid-based cytology) samples from 204 women were analyzed for HPV DNA and mRNA with the in-house real-time PCR as well as PreTect HPV-Proofer. The sensitivity of real-time PCR mRNA detection to identify histologically confirmed CIN2+ (cervical intraepithelial neoplasia, grade 2 or higher) was 0.91, compared to 0.95 for DNA analysis. The specificity was 0.68 compared to 0.38, and the positive predictive value (PPV) was higher for mRNA (0.67 versus 0.52) without any loss in negative predictive value (NPV). The sensitivity of the real-time PCR mRNA test was somewhat higher than that for PreTect HPV-Proofer (0.83 versus 0.75) in analyses for the same genotypes. The specificities were similar (0.76 versus 0.77). In analyses for mRNA of the eight most common genotypes in cervical cancer (HPV16, -18, -31, -33, -35, -45, -52, and -58), the sensitivity of detection of CIN2+ lesions was 0.87 and the specificity 0.74, with a PPV of 0.70. In conclusion, real-time PCR for detection of HPV E6/E7 mRNA transcripts can be a sensitive and specific tool in screening and investigation of cervical neoplasia. The composition of HPV types in mRNA testing needs to be further investigated to optimize sensitivity and specificity.

Differential methylation of the HPV 16 upstream regulatory region during epithelial differentiation and neoplastic transformation

High risk human papillomaviruses are squamous epitheliotropic viruses that may cause cervical and other cancers. HPV replication depends on squamous epithelial differentiation. Transformation of HPV-infected cells goes along with substantial alteration of the viral gene expression profile and preferentially occurs at transformation zones usually at the uterine cervix. Methylation of the viral genome may affect regulatory features that control transcription and replication of the viral genome. Therefore, we analyzed the methylation pattern of the HPV16 upstream regulatory region (URR) during squamous epithelial differentiation and neoplastic transformation and analyzed how shifts in the HPV URR methylome may affect viral gene expression and replication. HPV 16 positive biopsy sections encompassing all stages of an HPV infection (latent, permissive and transforming) were micro-dissected and DNA was isolated from cell fractions representing the basal, intermediate, and superficial cell layers, each, as well as from transformed p16^INK4a-positive cells. We observed fundamental changes in the methylation profile of transcription factor binding sites in the HPV16 upstream regulatory region linked to the squamous epithelial differentiation stage. Squamous epithelial transformation indicated by p16^INK4a overexpression was associated with methylation of the distal E2 binding site 1 leading to hyper-activation of the HPV 16 URR. Adjacent normal but HPV 16-infected epithelial areas retained hyper-methylated HPV DNA suggesting that these viral genomes were inactivated. These data suggest that distinct shifts of the HPV 16 methylome are linked to differentiation dependent transcription and replication control and may trigger neoplastic transformation.

HPV16 E2 could act as down-regulator in cellular genes implicated in apoptosis, proliferation and cell differentiation

Background

Human Papillomavirus (HPV) E2 plays several important roles in the viral cycle, including the transcriptional regulation of the oncogenes E6 and E7, the regulation of the viral genome replication by its association with E1 helicase and participates in the viral genome segregation during mitosis by its association with the cellular protein Brd4. It has been shown that E2 protein can regulate negative or positively the activity of several cellular promoters, although the precise mechanism of this regulation is uncertain. In this work we constructed a recombinant adenoviral vector to overexpress HPV16 E2 and evaluated the global pattern of biological processes regulated by E2 using microarrays expression analysis.

Results

The gene expression profile was strongly modified in cells expressing HPV16 E2, finding 1048 down-regulated genes, and 581 up-regulated. The main cellular pathway modified was WNT since we found 28 genes down-regulated and 15 up-regulated. Interestingly, this pathway is a convergence point for regulating the expression of genes involved in several cellular processes, including apoptosis, proliferation and cell differentiation; MYCN, JAG1 and MAPK13 genes were selected to validate by RT-qPCR the microarray data as these genes in an altered level of expression, modify very important cellular processes. Additionally, we found that a large number of genes from pathways such as PDGF, angiogenesis and cytokines and chemokines mediated inflammation, were also modified in their expression.

Conclusions

Our results demonstrate that HPV16 E2 has regulatory effects on cellular gene expression in HPV negative cells, independent of the other HPV proteins, and the gene profile observed indicates that these effects could be mediated by interactions with cellular proteins. The cellular processes affected suggest that E2 expression leads to the cells in to a convenient environment for a replicative cycle of the virus.

Prognostic Implication of High Risk Human Papillomavirus E6 and E7 mRNA in Patients with Intraepithelial Lesions of the Cervix in Relationship to Age

Since the introduction of the cytological screening programs, a significant reduction in the incidence of cervical cancer has been achieved. Almost all of these cancers are related to high-risk (HR) Human Papillomavirus (HPV) cervical infections. However, the natural history of HPV infection seems to be different in younger patients, resulting in a higher rate of regression. There is, therefore, the need to identify HPV-related biomarkers in order to enhance the effectiveness of screening of high-risk cytological lesions, in particular in women over 35 years of age. This study aims to evaluate the prognostic value of the HR HPV E6 and E7 mRNA expression in women with intraepithelial lesions of the cervix, older or younger than 35 years of age. One hundred and eighty-four HR HPV DNA positive patients with a low squamous intraepithelial lesion (LSIL) were tested for mRNA expressions, included in an observational study, and evaluated at follow-up with standard cytology up to 24 months from the mRNA test. The frequency of HSIL/LSIL cytology in the older cohort of mRNA positive patients was significantly higher compared to mRNA-negative patients, both at 1 and 2 years of follow-up ( Chi-square: p 0.007 and p 0.009), but this difference was not found in the younger cohort. According to our results, the E6/E7 mRNA test could be a biomarker for viral activity, useful in identifying patients at higher risk of abnormal cytology, and in implementing the management of HR HPV DNA-positive women over 35 years of age.

State of HPV16 integration in Lithuanian women with cervical neoplasia

Cervical cancer morbidity and mortality in Lithuania is one of the biggest in the European Union. The main risk factor of cervical cancer is human papillomavirus (HPV). The deletion of the HPV E2 gene influences HPV DNA integration into the cell genome, as well as a rapid progression of cervical lesions. The purpose of this study is to determine HPV, its types, and HPV 16 integration in different grades of cervical intraepithelial neoplasias (CIN). 253 women with cytological lesions were involved in the study. After a histology, 31 women were diagnosed with CIN I, 35 with CIN II, and 51 with CIN III. The biggest prevalence of HPV infection was detected in women younger than 25 years old (69.7%) and in women with CIN II (90.9%). HPV 16 was detected in 67.8% of all cases, with the highest prevalence in CIN III (84.4%). A partial integration form was detected in 65.0% of HPV 16 infected women, a complete virus integration in 26.5%, and an episomal form in 8.4% of cases. Our study concludes that in all the cases confirmed using a histology, the partial virus integration form of CIN was identified the most. It was less frequently detected in CIN I cases (60.0%), but more frequently in CIN II and CIN III cases (72.8 and 69.3%, respectively).

Pathology and epidemiology of HPV infection in females

Human papillomaviruses (HPVs) are a large family of small double-stranded DNA viruses that infect squamous epithelia. It has been established that infection with specific HPV types is a contributing factor to different types of anogenital cancer, including vulval, vaginal, anal, penile, and head and neck cancers. Approximately 4% of all cancers are associated with HPV. HPV infection is the major cause of cervical cancer and genital warts. Genital HPV infections are very common, are sexually transmitted, and have a peak prevalence between ages 18 and 30. Most of these infections clear spontaneously, but in 10-20% of women, these infections remain persistent and are at risk of progression to grade 2/3 cervical intraepithelial neoplasm (CIN) and eventually to invasive cancer of the cervix (ICC). CINs are genetically unstable lesions with a 30-40% risk of progression to ICC. If left untreated, they form a spectrum of increasing cytological atypia, ranging from low-grade CIN1 to high-grade CIN3; the latter are caused almost exclusively by high-risk HPVs, HPV 16 and 18. Infection with HPV requires a microabrasion in the genital epithelium. The oncogenic properties of high-risk HPV reside in the E6 and E7 genes, which if inappropriately expressed in dividing cells deregulate cell division and differentiation. HPV DNA testing has been shown consistently to be superior to cytology in terms of sensitivity and positive predictive value and will become a major tool in cervical cancer screening, at least in the developed countries.

Human papillomavirus and colorectal cancer: evidences and pitfalls of published literature

PURPOSE

The aim of this study is to review published literature regarding a possible role of human papillomavirus (HPV) infection in colorectal cancer in order to understand if HPV infection plays an active role in colorectal carcinogenesis and to highlight evidences and pitfalls of published studies.

METHODS

We reviewed literature by searching PubMed, Ovid, and the Cochrane databases for published series investigating HPV and colorectal cancer from 1988 to date.

RESULTS

Twenty-one studies investigating a possible correlation between HPV infection and colon cancer have been published. We reviewed 15 case-control studies and six studies investigating a possible role for HPV virus in colorectal carcinogenesis. HPV was detected in the majority of reported series with a significant difference in HPV infection between tumors and disease-free controls or tumor-adjacent tissue; the HPV mean detection rate within carcinomas was 41.7%, comparing to a mean detection rate of 32.8% in adjacent colic mucosae, and 5.8% in disease-free controls (Chi-square test, p = 0.001). The correlation between HPV infection and c-myc amplification, k-ras mutation, and p53 polymorphism or mutations has been investigated; however, the possible role of HPV in colorectal carcinogenesis was not defined.

CONCLUSIONS

HPV has been detected in the majority of reported series, but published literature lacks in definitive data regarding standard methods of investigation and stratification of groups and population. These data encourage further studies with the aim to investigate the presence of the virus in larger series, its possible role in oncogenesis, the integration in host genome, the expression of viral oncoproteins, the mutations in HPV positive cancers and routes of colon infection (hematologic/lymphatic spreading or perineal diffusion).

HPV-DNA integration and carcinogenesis: putative roles for inflammation and oxidative stress

HPV-DNA integration into cellular chromatin is usually a necessary event in the pathogenesis of HPV-related cancer; however, the mechanism of integration has not been clearly defined. Breaks must be created in both the host DNA and in the circular viral episome for integration to occur, and studies have shown that viral integration is indeed increased by the induction of DNA double strand breaks. Inflammation generates reactive oxygen species, which in turn have the potential to create such DNA strand breaks. It is plausible that these breaks enable a greater frequency of HPV-DNA integration, and in this way contribute to carcinogenesis. Consistent with this idea, co-infections with certain sexually transmitted diseases cause cervical inflammation, and have also been identified as cofactors in the progression to cervical cancer. This article examines the idea that inflammation facilitates HPV-DNA integration into cellular chromatin through the generation of reactive oxygen species, thereby contributing to carcinogenesis.

Rolling circle replication of human papillomavirus type 16 DNA in epithelial cell extracts

Replication of human papillomavirus (HPV) genomes requires an origin of replication and two viral proteins: the DNA helicase E1 and the auxiliary factor E2. To dissect the profile of HPV replication in the epithelium, we analyzed replication of an HPV16 origin-containing plasmid in human epithelial cell extracts supplemented with purified E1 and E2. We found that in addition to well-defined circular replication products, high-molecular-weight DNA was synthesized in a manner that depended on the origin, E1 and E2. The high-molecular-weight DNA was converted to a unit-length linear DNA by treatment with restriction enzymes that cleave the plasmid once, implying that a concatemeric DNA was generated by rolling circle replication. Nicking or relaxing the template plasmid enhanced the level of HPV rolling circle replication. In contrast, the addition of an extract from non-epithelial cells diminished the generation of the rolling circle replication product in the epithelial cell extract, indicating factors that counteract HPV rolling circle replication. These results suggest a rolling circle replication mechanism for the HPV genome in cervical epithelial cells, which may have physiological implications for generation of the tandem-repeated HPV genomes occasionally found integrated into the chromosome of cervical cancer cells.

Episomal and integrated human papillomavirus type 16 loads and anal intraepithelial neoplasia in HIV-seropositive men

OBJECTIVES

To assess levels of episomal and integrated human papillomavirus type 16 (HPV-16) loads in HIV-seropositive men who have sex with men (MSM) in anal infection and to study the association between episomal and integrated HPV-16 loads and anal intraepithelial neoplasia (AIN).

STUDY DESIGN

A cohort study of 247 HIV-positive MSM followed each 6 months for 3 years. Overall, 135 (54.7%) men provided 665 HPV-16-positive anal samples.

METHODS

Episomal and integrated HPV-16 loads were measured with quantitative real-time PCR assays. HPV-16 integration was confirmed in samples with a HPV-16 E6/E2 of 1.5 or more with PCR sequencing to demonstrate the presence of viral-cellular junctions.

RESULTS

The HPV-16 DNA forms in anal samples were characterized as episomal only in 627 samples (94.3%), mixed in 22 samples (3.3%) and integrated only in nine samples (1.4%). HPV-16 episomal load [odds ratio (OR) = 1.5, 95% confidence interval (CI) 1.1-2.1], number of HPV types (OR = 1.4, 95% CI 1.1-1.8) and current smoking (OR = 4.8, 95% CI 1.3-18.6) were associated with high-grade AIN (AIN-2,3) after adjusting for age and CD4 cell counts. Integrated HPV-16 load was not associated with AIN-2,3 (OR = 0.7, 95% CI 0.4-1.1). Considering men with AIN-1 at baseline, four (16.7%) of the 24 men who progressed to AIN-2,3 had at least one sample with integrated HPV-16 DNA compared with three (23.1%) of 13 men who did not progress (OR = 0.7, 95% CI 0.2-3.8; P = 0.64). Integration was detected in similar proportions in samples from men without AIN, with AIN-1 or AIN-2,3.

CONCLUSION

High episomal HPV-16 load but not HPV-16 integration load measured by real-time PCR was associated with AIN-2,3.

Human papillomavirus and oropharynx cancer: biology, detection and clinical implications

OBJECTIVES

To review evidence for the role of human papillomavirus (HPV) in the etiology of oropharyngeal cancers, methods of viral detection, and the resulting clinical implications.

STUDY DESIGN

Contemporary review.

METHODS

Published journal articles identified through PubMed and conference proceedings were reviewed.

RESULTS

HPV-associated squamous cell carcinomas represent a distinct disease entity from carcinogen-associated squamous cell carcinomas. HPV oncoproteins lead to mucosal cell transformation through well-defined mechanisms. Different methods of detecting HPV exist with variable levels of sensitivity and specificity for biologically active virus. Although virus is detected in a number of head and neck subsites, studies demonstrate improved outcomes in HPV-associated carcinoma of the oropharynx only. The cell cycle regulatory protein p16 is upregulated by biologically active HPV and serves as a biomarker of improved response to therapy.

CONCLUSIONS

HPV-associated squamous cell carcinoma of the oropharynx is a biologically distinct entity from carcinogen-associated carcinoma. Understanding the molecular mechanisms behind the improved outcomes in patients with HPV-associated oropharyngeal carcinoma may lead to novel therapeutics for patients with carcinogen-associated carcinomas.

Viral hit and run-oncogenesis: genetic and epigenetic scenarios

It is well documented that viral genomes either inserted into the cellular DNA or co-replicating with it in episomal form can be lost from neoplastic cells. Therefore, "hit and run"-mechanisms have been a topic of longstanding interest in tumor virology. The basic idea is that the transient acquisition of a complete or incomplete viral genome may be sufficient to induce malignant conversion of host cells in vivo, resulting in neoplastic development. After eliciting a heritable change in the gene expression pattern of the host cell (initiation), the genomes of tumor viruses may be completely lost, i.e. in a hit and run-scenario they are not necessary for the maintenance of the malignant state. The expression of viral oncoproteins and RNAs may interfere not only with regulators of cell proliferation, but also with DNA repair mechanisms. DNA recombinogenic activities induced by tumor viruses or activated by other mechanisms may contribute to the secondary loss of viral genomes from neoplastic cells. Viral oncoproteins can also cause epigenetic dysregulation, thereby reprogramming cellular gene expression in a heritable manner. Thus, we expect that epigenetic scenarios of viral hit and run-tumorigenesis may facilitate new, innovative experiments and clinical studies in spite of the fact that the regular presence of a suspected human tumor virus in an early phase of neoplastic development and its subsequent regular loss have not been demonstrated yet. We propose that virus-specific "epigenetic signatures", i.e. alterations of the host cell epigenome, especially altered DNA methylation patterns, may help to identify viral hit and run-oncogenic events, even after the complete loss of tumor viruses from neoplastic cells.

Human papillomavirus genome integration in multifocal vulvar Bowen's disease and squamous cell carcinoma

Human papillomavirus (HPV) is an important aetiological agent in cervical carcinomas and in malignant skin tumours. Integration of the HPV DNA into host genome is one of the most important risk factors for malignant transformation. We report a patient with multiple black plaques and an erythematous nodule on her vulva. On histological examination, multifocal vulvar Bowen's disease (BD) and invasive squamous cell carcinoma (SCC) were found. An amplification of papillomavirus oncogene transcripts (APOT) assay showed that two locations of BD had only episome-derived HPV16 transcripts, but the other two sites of BD and the nodule of invasive SCC had HPV16 transcripts derived from integration. Sequencing analysis revealed that the invasive SCC had its integration site at 8q24, the Myc locus. Our results suggest that the APOT assay in multiple sites of the same patient may be a valuable tool for evaluation of the clinical degree of malignancy for vulvar BD.

Prevalence of human papillomavirus 16/18/33 infection and p53 mutation in lung adenocarcinoma

Human papillomavirus (HPV) infection is a causative event for the development of uterine cervical carcinoma. Human papillomavirus (HPV) 16, 18, and 33 DNA has been also detected frequently in lung adenocarcinomas (AdCs) in East Asian countries; however, its prevalence in Japan remains unclear. We therefore screened for HPV 16/18/33 DNA in 297 lung AdCs in a Japanese population by multiplex PCR with type-specific primers. As reported previously, HPV 16 DNA was detected in two cervical cancer cell lines, CaSki and SiHa, while HPV 18 DNA was detected in HeLa cells, and 0.1-1.0 copies of HPV-DNA per cell were detectable by this method. However, with this method, none of the 297 lung AdCs showed positive signals for HPV 16/18/33 DNA, indicating that HPV-DNA is not or is very rarely integrated in lung AdC genomes in the Japanese. Furthermore, none of the lung AdCs showed positive signals by nested PCR with HPV 16/18 type-specific primers. Therefore, we further attempted to detect HPV 16/18/33 DNA in 91 lung cancer cell lines, including 40 AdC cell lines. Among them, 30 have been established in Japan and the remaining 61 in the USA. No HPV signals were obtained in any of the 91 cell lines by either multiplex or nested PCR, while the p53 gene was mutated in 81 of them including 35 of the 40 AdC cell lines. These results indicate that HPV 16/18/33 infection does not play a major role in the development of lung AdC in Japan nor in the USA.

Human papillomavirus 16 integration and risk factors associated in anal samples of HIV-1 infected men

BACKGROUND

The integration of HPV-16 DNA into the host genome is considered an important event in the progression of premalignant cervical lesions to cervical cancer. The aim of our study was to assess the prevalence of HPV-16 integration in anal cytologic specimens of HIV-1 infected men and its association with risk factors. PATIENTS METHODS: This cross-sectional study included 269 HIV-infected males. Detection and typing of HPV-infection was done by multiplex PCR, and integration of HPV-16 by real-time PCR.

RESULTS

The overall anal HPV-infection prevalence was 78% (209/269), 29% (77/269) for HPV-16 infection, and 9% (25/269) for HPV-16 integration. In HPV-16 infected group, the integration prevalence represented 32% (25/77). The only risk factor associated with HPV-16 integration was the time since HIV diagnosis (OR = 1.2, 95% CI: 1.0-1.3; P = 0.010). The risk factors associated with abnormal cytology results were: HPV infection (OR = 17.8, 95% CI: 6.8-46.6), HPV-16 infection (OR = 4.6, 95% CI: 2.5-8.4), and presence of HPV-16 integrated forms (OR = 11.7, 95% CI: 1.5-93.5). Moreover, in the multivariate analysis, the HPV-16 integration continued representing the most important risk factor (OR = 20, 95% CI: 1.6-226) for anal cytologic abnormalities.

CONCLUSION

HPV-16 infection and its integration in anal cells were highly prevalent in HIV-infected men. The assessment of HPV-16 integration rather than HPV-infection could be a good biomarker for predicting anal precancerous lesions in HIV-positive men.

Human papillomavirus detection and typing in thin prep cervical cytologic specimens comparing the Digene Hybrid Capture II Assay, the Roche Linear Array HPV Genotyping Assay, and the Kurabo GeneSquare Microarray Assay

Three methods for the detection of HPV DNA were compared in cervical cytologic specimens: the Digene Hybrid Capture II Assay (HC), the Roche Linear Array HPV Genotyping Assay (LA) and the Kurabo GeneSquare Microarray (GS). The main goals of the study were to correlate cytology with HPV detection and to determine agreement between assay pairs for HPV detection. Thin-prep Pap smears were performed and supernates were tested by HC, LA, and GS. For specimens reacting with the HPV 52/33/35/58 probe in the LA assay, type-specific PCR was performed for HPV types 52, 33, 35, or 58. Binomial proportions and kappa coefficients were calculated for agreement between assays. Cytology results and supernatant were available for 202 subjects. HPV detection increased with worsening cytologic abnormality in all three assays. For all cytologic groups, LA and GS detected more HPV (all and oncogenic) than HC. However, for detection of oncogenic HPV types represented in all three assays, differences between assays were less pronounced. The highest agreement was between LA and GS. In four of 12 specimens reacting with the HPV 52/33/35/58 probe in the LA assay but deemed HPV 52-LA-negative using an algorithm provided by the manufacturer, the presence of HPV 52 was confirmed using type-specific HPV 52 PCR. All four of these specimens were also GS-positive for HPV 52.